SEATTLE - The Chicago Cubs placed Ryan Sweeney on the 15-day disabled list Sunday and he is expected to miss at least the next six weeks after fracturing a rib while making a catch in Saturday night's game between the Cubs and Seattle Mariners.

Sweeney was injured making a third-inning catch of a Kendry Morales fly ball to center field. Sweeney caught the drive on the warning track and then appeared to glance off the outfield fence. Initial x-rays Saturday night were negative for a fracture. A CT scan on Sunday, however, showed the break.

"It felt like a brick wall," Sweeney told Paul Sullivan of the Chicago Tribune before Sunday's game between the Cubs and Mariners. "I probably grabbed my side because I felt it jolt a little bit. I feel like I've hit that wall before and it wasn't that hard. It must have just hit me in the (wrong) spot."

Sweeney batted .295 with four home runs and 15 RBI in 44 games for the Cubs since being recalled from Triple-A Iowa on May 6. He was signed by the Cubs after he was released by the Red Sox at the end of spring training.

Sweeney had started the past 14 games in center field after David DeJesus suffered a dislocated shoulder running into a wall against the Mets at Citi Field in New York.

Sveum told the Tribune the loss of Sweeney is a huge blow for the Cubs.

"Obviously a .900 OPS against right-handed pitching, he's been doing a great job," Sveum said. "It's unfortunate because we started getting things going a little bit with the offense, and now we lose a big piece of that. It's unfortunate for him too, because he's trying to get his career going and is getting a chance to play every day.

"It stinks when those things happen to guys like that who are really good players and get a chance and all of sudden it's taken away from him for a couple months."

Sweeney also expressed his disappointment. He suffered a concussion in May last season while making a diving catch for the Red Sox, then broke his hand and missed the last two months after punching a dugout wall. His performance with the Cubs seemed to have him back on track to where he was three years ago when he was an up-and-coming star for the Oakland Athletics before suffering a knee injury that prematurely ended his 2010 campaign.

"It's frustrating," Sweeney toldd the Tribune. "It seems like every year ... I was just happy the Cubs gave me the opportunity to play again every day. Last year I got a concussion when I was hitting .350, so it seems like it comes at the worst time for me.

"I tried to do what I could when I was playing. I play hard, so it's not like I was out of control when I hit the wall. It was just like a freak thing, I guess."

Sweeney, 28, is an eight-year major league veteran with a career .281 batting average. He prepped at Jefferson and Xavier, graduating from Xavier in 2003. The Chicago White Sox selected him in the second round of the June 2003 First Year Player Draft and he turned down a scholarship offer from San Diego State to sign a professional contract.